Chemistry Flashcards

Question

What is the rule for displacement reactions?

Answer 1

The more reactive metal displaces the less reactive metal

Answer 2

Indicator Acid Neutral Alkali Universal red green purple Blue litmus red blue blue Red litmus red red blue Phenolphthalein colourless colourless pink

Answer 3

Copper oxide | Sodium hydroxide

Answer 4

Salt and hydrogen

Answer 5

Limewater bubbles and turns milky

Answer 6

Light a splint and hold it in the testube. It will relight.

Answer 7

The splint in the gesture makes a pop sound. The "pop test"

Answer 8

Carbon dioxide Hydrogen Oxygen

Answer 9

Mixtures are easier to separate and don't have a fixed position.

Answer 10

The different component melt at different times so it takes a while E.g. Some parts of butter melt while others are solid.

Answer 11

E.g. Ice. | It remains the same temp until it has melted to a liquid.

Answer 12

It's used to separate a solid from a liquid. The solid on the filter paper is called the residue.

Answer 13

After filtration, the solution of solvent and solute is separated by evaporation e.g. Salt and water.

Answer 14

It's to separate different coloured dyes. A spot of ink is put on filter paper and the water separates it because each dye has a different solubility

Answer 15

When a solution is heated, water boils and water vapour is formed. The vapour cools and condenses to a liquid in a beaker and is called 'distiller water'

Answer 16

To separate two or more liquids from each other e.g. Water and alcohol because they have different boiling points.

Answer 17

A compound

Answer 18

A molecule

Answer 19

Change in temperature Change in colour Gas produced - bubbles

Answer 20

Of the same element

Answer 21

A compound.

Answer 22

``` Oxide Fluoride Bromide Iodide Sulphide ```

Answer 23

Hydroxide | Sodium hydroxide = NaOH

Answer 24

2 as in 2 oxygen.

Answer 25

Carbon + oxygen = carbon dioxide

Answer 26

Copper 1 Sulphate. 1 Oxygen 4

Answer 27

A bond formed between metals and non-metals by giving or gaining electrons.

Answer 28

Protons (positive) Neutrons (neutral) Electrons (negative)

Answer 29

Something made entirely of the same atom and can't be broken down into anything more. They're pure.

Answer 30

A bond formed between 2 non-metals by sharing electrons.

Answer 31

2 elements

Answer 32

3 elements (including oxygen)

Answer 33

Alkaline metals

Answer 34

Halogen non-metals

Answer 35

Noble unreactive gases

Answer 36

Circles for shells | Crosses as the electrons, drawn on in quarters

Answer 37

H2 + O2 -> H2 O H2 + O2 -> 2H2 O 2H2 + O2 -> 2H2 O

Answer 38

A different form of the same element

Answer 39

Atomic (proton) number

Answer 40

Atomic mass (number of protons and neutrons)

Answer 41

The number of electrons is the same as the number of protons (positives and negatives attract)

Answer 42

Protons +1 Neutrons 0 Electrons -1

Answer 43

A molecule that travels in pairs e.g. Oxygen

Answer 44

Calcium oxide and carbon dioxide | CaO & CO2

Answer 45

Calcium hydroxide | Ca(OH)2

Answer 46

A mix of cement and water with sand and gravel.

Answer 47

The can has a gap between the cup wall and the wall which holds the food or drink. In the gp, there is a sachet of calcium oxide which, when the can is opened and water is released in the gap, will react with the calcium oxide and produce heat.

Answer 48

Exothermic

Answer 49

It glows and breaks down into a power substance. This is called thermal decomposition.

Answer 50

A substance breaking down due to heat.

Answer 51

A chloride

Answer 52

Sodium carbonate NaCO3 Copper carbonate CuCO3 Zinc carbonate ZnCO3

Answer 53

Limestone and clay

Answer 54

It reacts with water (called hydration)

Answer 55

Hydration takes a while so, even if the cement is strong, more bonds will form and it will become stronger.

Answer 56

Weaker. Purer cement is stronger.

Answer 57

Limestone is on demand and is needed everyday for daily use. It provides jobs Helps the economy as it provides/makes money

Answer 58

They're ugly and unpopular, reducing numbers such as tourists and house prices They cause a lot of traffic, noise and pollution which affects locals It destroys animals, habitats, wildlife and a natural area which can never be properly replaced

Answer 59

An area like a deep pit where stone and various other materials are extracted from the soil.

Answer 60

Small stones and gravel (used for concrete)

Answer 61

A solid element or compound found in the earth's crust

Answer 62

A rock or mineral containing enough metal to make extraction worthwhile.

Answer 63

Coins, piping, wiring, pins.

Answer 64

Tubes, cutlery, cans, steel.

Answer 65

Cooking foil, drink cans, bottle tops.

Answer 66

Fertilizer, detergents, to harden rubber.

Answer 67

Protection from rust

Answer 68

Jewellery and computer circuits.

Answer 69

When a more reactive metal boots out a less reactive metal e.g. Iron + copper sulphate = iron sulphate + copper

Answer 70

Biomass, coal and wood

Answer 71

When oxygen is removed from from a substance e.g. Metal oxide + reduction = metal

Answer 72

When oxygen is added to a substance e.g. Copper oxide + carbon = carbon dioxide + copper

Answer 73

Copper oxide is reduced and carbon is oxidised.

Answer 74

Because carbon is more reactive.

Answer 75

Heat it, resulting in thermal decomposition

Answer 76

It is like a oven, heated up to 1900'c, in the form of a tower into which a blast of hot compressed air can be introduced from below. Such furnaces are used chiefly to make iron from a mixture of iron ore, coke, and limestone.

Answer 77

Carbon/coke/coal, limestone and iron ores are put into the top. Hot air is blasted from the bottom. Carbon/coke + oxygen/air = carbon dioxide Carbon dioxide + carbon = carbon monoxide Iron oxide + carbon monoxide = iron + carbon dioxide Limestone is used to remove impurities in the form of slag. Iron is reduced. Carbon is oxidised.

Answer 78

It reacts with the oxygen and becomes oxidised.

Answer 79

Molten iron from the blast furnace 96% iron - not pure - contains carbon and slag Hard, strong, doesn't rust, brittle - arranged in an irregular pattern Used for strength not flexibility

Answer 80

100% iron - pure Very soft - arranged in a regular pattern Malleable

Answer 81

Doesn't rust Alloy - nickel and chromium Expensive

Answer 82

0.2% carbon Malleable Used for car bodies and wires

Answer 83

0.6 - 1.5% carbon Very hard Used for tools

Answer 84

``` Good conductors of heat Good conductors of electricity High melting and boiling points (except mercury) Shiny (when freshly cut - lustrous) Can be malleable Can be ductile Some are magnetic Some are sonorous Some are strong and dense ```

Answer 85

It is another way to extract metals, which are very reactive, by splitting up a substance or compound by using electricity. It is chemical decomposition produced by passing an electric current through a liquid or solution containing ions. Electrolysis is the process by which ionic substances are broken down into simpler substances using electricity. During electrolysis, metals and gases may form at the electrodes. What is electrolysis? Ionic substances contain charged particles called ions. For example, lead bromide contains positively charged lead ions and negatively charged bromide ions. Electrolysis is the process by which ionic substances are decomposed (broken down) into simpler substances when an electric current is passed through them. (Ionic bond/substance is between a metal and a non metal) For electrolysis to work, the ions must be free to move. Ions are free to move when an ionic substance is dissolved in water or when melted. For example, if electricity is passed through molten lead bromide, the lead bromide is broken down to form lead and bromine. Here is what happens during electrolysis: Positively charged ions move to the negative electrode during electrolysis. They receive electrons and are reduced. Negatively charged ions move to the positive electrode during electrolysis. They lose electrons and are oxidised. The substance that is broken down is called the electrolyte. (The cathode is negative and the anode is positive)

Answer 86

It is an alternative way to extract copper by using low grade copper ores (which aren't worth while) and a combination of biological and chemical processes. Sulphuric acid dissolves the copper ions and runs of as slag where it's collected and extracted by displacement or electrolysis; all due to bacteria.

Answer 87

Pros Low cost Less pollution and energy Doesn't need much land (doesn't scar the environment) Cons Doesn't recover precious metals Sometimes acid is needed which can cost a lot Sometimes bacteria itself produces too much acid and must be neutralised which costs Slow

Answer 88

It is another way to extract copper from it's ore. This is done by plants absorbing the elements through their roots and into the stem and leaves when they become more concentrated and are then burned, producing an ash rich with the compound.

Answer 89

``` Pros Recovers precious metals Takes metals out of the ground which helps the environment Not very expensive Easy to monitor ``` ``` Cons Dependent on the weather & survival of plants Requires a lot of land Takes a long time Hard to make completely pure ```

Answer 90

``` Saves energy Saves money Doesn't require digging Conserves the environment We are running out of metals ```

Answer 91

It's a very important fossil fuel used to make plastics made up of a mixture of different compounds.

Answer 92

It's made from the bodies of tiny sea creatures and plants that died roughly 150 million years ago. They were buried beneath layers of sand and stilt on the sea bed and didn't decay normally as bacteria feeding on them had little to no oxygen. As the pressure and temperature increased, oil was formed. Crude oil itself is useless therefore must be separated. Natural gas is usually found with crude oil.

Answer 93

Fractions | Different groups of hydrocarbons based on their boiling points.

Answer 94

They are saturated hydrocarbons made from crude oil. Cn 2n+2

Answer 95

They are hydrocarbons with a carbon double bond meaning they can separate and become saturated therefore alkenes are unsaturated. Cn H2n

Answer 96

``` Methane - CH4 Ethane - C2H6 Propane - C3H8 Butane - C4H10 Pentane - C5H12 ```

Answer 97

A process used to separate a mixture of liquids that have different boiling points. This can be used for crude oil as crude oil is made up of different compounds with different boiling points.

Answer 98

Fuels with small molecules which are colourless, runny and highly flammable.

Answer 99

Fuels with medium sized molecules which are a yellowish colour, are quite thick and quite hard to light - a bit of smoke.

Answer 100

Fuels with large molecules which are a dark orange colour, are quick thick (viscous) and are difficult to light - quite a smokey flame.

Answer 101

1) When hydrocarbons and completely combusted, carbon dioxide (and water) is produced which contributes to global warming and greenhouse gasses as well as minority contributing to acid rain. 2) If incomplete combustion occurs - when it hasn't completely burned or there isn't enough oxygen/air or the amount is limited, carbon monoxide is produced which is an extremely deadly, toxic gas. 3) Ash and carbon (soot) may form too due to incomplete combustion. This can then form solid particles containing carbon and hydrocarbons, known as particulates, which cause global dimming, meaning they reflect the sunlight (back). 4) Fossil fuels often have sulphur and/or nitrogen compounds which, when burned, can combine with the air at high temperatures to form acid rain.

Answer 102

Sulphur can be removed from waste gasses as the waste gasses are mixed with powdered limestone. The SO2 then reacts with it to form calcium sulphate. Catalytic converters for cars also stop/reduce carbon monoxide and nitrogen oxide from going into the environment and filters can be used to remove particulates.

Answer 103

``` Petroleum gases Petrol Kerosine Diesel Lubricating oil Heavy fuel oil Bitumen ```

Answer 104

Combustion

Answer 105

As crude oil itself is useless, it must be separated into fractions. These fractions, such as petrol, are achieved by fractional distillation. They way this process works is that, within a large column, crude oil is heated to approx 400°C causing most of the compounds within crude oil to evaporate into vapours. Small molecules with low boiling points are collected at the top and large molecules with high boiling points are collected at the bottom. Those with large molecules that don't evaporate remain liquid. As the different compounds have different melting and boiling points, they also cool and condense at different stages, resulting in separated fractions. As petrol has quite small molecules and and a low boiling point, it condenses at the top of the column, the coolest part, turning back into a liquid but now it is a fraction on it's own - separated.

Answer 106

The process when large molecules and heated and thermally decomposed, forming smaller, more useful hydrocarbons using a catalyst (something which speeds up an experiment) often forming alkenes. An example of this is when decane goes through the process of cracking, forming smaller, more useful substances. Decane -heat-> octane + ethene C10H22 -> C8H18 + C2H4

Answer 107

An alkene is formed.

Answer 108

The bromine water test when (yellow) bromine water is added to the substance and changes colour (to colourless) if an alkene is present or not.

Answer 109

Small reactive molecules that react together in repeating sequences to form a very large molecule (polymer).

Answer 110

A substance made from very large molecules made up of a chain/many repeating units e.g. Poly ethene Big molecules made up from small molecules - monomers.

Answer 111

The reaction of monomers (small molecules) to make a polymer (large molecule).

Answer 112

H H \ / C = C Monomer = means double bond / \ n. means number n. H H Polymerisation = ``` ( H H ) ( \ / ) ( - C - C - ) ( / \ ) ( H H ) n. ```

Answer 113

Plastics are made by joining small molecules together end to end to make long chain molecules. The small single molecules are called monomers and the long chain molecules are called polymers. (Poly meaning many within chemistry). So the plastic poly-ethene is made from ethene (monomer). The process of joining the molecules up is called polymerisation.

Answer 114

The arrangement of the polymer chains

Answer 115

Thermo-softening and thermosetting. Thermo-softening polymer chains are described like spaghetti as they are loose and everywhere with weak forces between separate polymer chains. Thermosetting polymer chains are rigid and are fixed together by strong bonds called cross linking.

Answer 116

Become soft and melt when heated Used when plastics need to be re shaped - can be re shaped by cooling and heating Can be recycled It will burn / ignite Long polymer chains not cross linked Used in bags, gutters and buckets (examples are polythene, PVC and Perspex)

Answer 117

Do not melt on heating but char Used when the object is likely to come into contact with heat Cannot be recycled Cannot be re shaped by heating and cooling Long polymer chains cross linked Used for light fittings, saucepan handles, kitchen work surfaces, tires etc (examples include Bakelite, melamine and Formica)

Answer 118

Polymers which have the ability to, once they've been shaped, change back to their original shape when the stimulus (commonly temperature) triggers the shape to change. It's often used for stitching wounds as it is heated by the body and can can shape to form the body. Smart polymers can also change colour.

Answer 119

Fibres used for fabrics are often coated with polymers to make them waterproof.

Answer 120

(As polymers have properties that make them specially suited for their purpose) polymers within hydrogels are highly hydrophilic, meaning they're attracted to water, which results in them being very flexible and absorbent. Used for nappies and wound dressings.

Answer 121

Fermentation and hydration of ethene.

Answer 122

Yeast is added to glucose (sugar) Enzymes (biological catalysts) cause the sugar to convert to ethanol and carbon dioxide. Glucose -yeast-> ethanol + carbon dioxide C6H12O6 -> 2C2H5OH + 2CO2

Answer 123

Ethene, obtained from the distillation and cracking of crude oil, is reacted with steam at a high pressure and temperature in the presence of a catalyst. Ethene + water -high pressure & phosphoric acid catalyst-> ethanol C2H4 + H2O -> C2H5OH

Answer 124

The waste isn't broken when left in the environment. This means it's unsightly, can harm wildlife and, even when out in landfill sites, it takes up a lot of valuable space.

Answer 125

Biodegradable plastics can decompose and break down due to microorganisms in the soil.

Answer 126

Cornstarch can be mixed into the plastic so that microorganisms can break down the cornstarch so the plastic breaks down into very small pieces that can be mixed with soil and compost. It can help make biodegradable plastics.

Answer 127